The firm introduced the technology to capture ratings data from services such as OnDemand Online and TV Everywhere – the latter developed by Time Warner and Comcast – which screen TV shows online in the same format they were shown on television.

The new meter uses the same technology as the people meters that track TV viewing and has currently been installed in 375 homes in the National People Meter panel. The firm said that the technology will be rolled out across people meter households throughout 2010, with full implementation in 2011.

Nielsen said it has also deployed the technology across its 230,000-strong online panel.

Sara Erichson (pictured), Nielsen’s president of media client services in North America, said: “OnDemand Online, TV Everywhere and similar offerings could provide the best way for video content providers to monetise TV programmes online. Importantly, these initiatives are very compatible with Nielsen’s television ratings system; that is, online audiences viewing these programmes could be included in Nielsen’s TV ratings.”

She said both services were examples of what Nielsen calls the “extended screen”, where a computer is classed as another TV-viewing screen within a household.

Erichson added that Nielsen would continue working on its other cross-platform ratings services, such as the TV/Internet Convergence Panel.

Last month the Financial Times reported that a group of media agencies and advertisers were planning a scheme to measure cross-platform viewing behaviour, including online video. Nielsen was quick to respond and sent a note to employees saying that ‘three-screen” (TV, online and mobile) measurement was at the centre of its strategy.

The next day, the firm announced that Time Warner had signed a seven-year deal to provide measurement services for all its business across three screens.